Apparatus for transporting and conditioning ready-mixed concrete



1932- E. A. HOFFMANN APPARATUS FOR TRANSPORTING AND CONDITIONING READY MIXED CONCRETE Filed July 15, 1951 2 Sheets-Sheet INVENTOR. Edward ,4. Hoffman/1 /Vm ZMWV ATTORNEY.

E. A. HOFFMANN 1,885,350

APPARATUS FOR TRANSPORTING AND CONDITIONING READY MIXED CONCRETE Nov; 1, 1932.

2 Sheets-Sheet 2 Filed July 13, 1931 IN V EN TOR.

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Patented Nov. 1 1932 UNITED STATES PATENT OFFICE EDWARD A. HOFFMANN, OF READING, PENNSYLVANIA Application filed July 13, 1931.

The present invention relates toimprovements in apparatus for transporting ready mixed concrete from a central mixing plant to the points where construction operations are being conducted. More specifically, the present invention relates to apparatus which is adapted to carry out the process described in my copending application Serial No. 262,- 789, and is a further improvement over the apparatus disclosed in my copencling appucatlon Serial No. 214,995.

The principal object of the invention is to provide an apparatus or more specifically a rotatable tank for carrying out the condition- ]5 ing process for concrete disclosed in my copending application Serial No. 262,789 which need not be raised at one end to discharge the so-treated concrete at the other or lower end.

By so doing, I eliminate entirely the hoist :10 mechanism such as heretofore used as disclosed, for instance, in my copending application Serial No. 214,995.

Otherobjects of the present invention and its resultant advantages will be apparent to those skilled in the art from the following specification and the drawings accompanying the same.

In the drawings, Fig. 1 is an elevational side view of a motor truck illustrating a preferred construction of a concrete conveying and conditioning tank made in accordance with the present invention mounted thereon, some of the standard and well-known constituent parts of the truck and its operating mechanism being shown in more or less diagrammatic form. Fig. 2 is an enlarged sectional view through the tank proper; Fig. 3 is an end view of the same showing the discharge opening; 7 1

Fig. 4 is a fragmentary sectional view through a wall section of the tank taken along the plane of line 44 in Fig. 2 showing the conditioning and moving means proper; and Figs. 5, 6 and 7 are similar sectional views of modified forms of the conditioning and moving means. 1

Like characters of reference denote similar parts throughout the several views and 0 the ollowing specification.

are of the usual commercial design.

obvious that the same may be rotated in either Serial No. 550,467.

In Fig. 1 a truckis shown having a bodyframe 10, a cab 11, an engine covered by a. hood 12 and wheels 13 and 14. These arts uitably mounted upon the frame 10 is a supplemental frame 15. The front end of supplemental frame 15 is extended upwardly at 16 to receive a trunnion 17 which is fastened to the center of the front part of a rotatable tank 18. The rear end of the tank is supported upon rollers 19. Near the front end w of the tank 18 is an annular gear 20 which is in mesh with a pinion 21 which is mounted upon a shaft 22, engaging a sprocket gear 23, which by means of a chain 24 meshes another sprocket gear 25 mounted upon a shaft 26 which connects to the transmission of the truck and serves as a power take-ofl' in the manner well known in the art. 27 is a clutch pedal in the cab which is connected by M suitable leverage to a bar 28 which in turn is connected. to an operating lever 29 fulcrumed preferably upon the supplemental frame 15 near the rear end of the tank 18. 30 is another operating lever having a common fulcrum with lever 29 which is connected by a bar 31 to an operating lever in the cab (not shown).

The tank 18 is rotatably-mounted and it is a right or left direction with respect to the so longitudinal axis of the tank, a clutch of any conventional form being in operative connection with the clutch pedal 27, so that the rotation in either direction may be accom plished by shifting of the levers at the rear end of the tank or by the ones in the cab, in the manner well known in the art.

We now revert to the rotatable tank 18 the details of which are shown in'Fig. 2. The tank is substantially cylindrical in shape, its rear end terminating conically at 32 defining a discharge opening 33. At a suitable point at the side of the tank is a filling opening covered by a closure 34 which is indicated diagrammatically only being preferably of the construction shown in Patent N 0. 1,735,- 683 issued to me on November 12,1929. With- 1n the tank welded to the side walls thereof are preferably two blades 35. These blades 19;;

l ta about three-quarters full with pre an l are spirally disposed within the tank and terminate at the outlet 33.

The cross section of a preferred form of the spirally disposed blade is shown in Fig. 4. The blade is pointed at its inner end and has a relatively broad base giving the blade asubstant-ially triangular cross section.

36 is a circular plate provided with a hand wheel 37 adjustable upon a screw-threaded shaft 38 anchored within a spider at the outlet 33. This closure is also to be interpreted as diagrammatic only; any commercial tank closure may be used, the only requirement bein that the closure must be water tight.

in the practicing of my process, it fill thi1 *8 concrete through the g opening at the side of the t covered by closure 34. While this is being done, the outlet 33 is closed tightly, of course. I then start the rotation of the tank 18 in the direction shown by an arrow in Fig. 41; marked conditioning. At this time then, the wet, flowable concrete within the ta is subjected to a slow rolling over motion which has the efiect of releasing all air entrained within the concrete during the violent agitation to which it is subjected during the mixing of the raw materials. This also prevents Stratification and setting of the concrete and further subjects the concrete to a conditioning treatment which causes the expulsion of the entrained air in the concrete and thereby greatly improves its quality, this process being the same as set forth in my copending application Serial No. 262,789. Attention is now particularly called to the angle of the blade 35 with respect to the cylindrical wall of the tank during the conditioning rotation. 'lhis blade is so disposed that it will not rupture the surface of the concrete when thus rotated but slides through the surface without rupturing it and so does not violently agitate the mixture as is the case with the usual form and angle of agitating blades of concrete mixers.

In order to discharge the tank after the destination is reached, the direction of rotation is reversed to correspond to that marked with an arrow in Fig. 4 and designated discharging. The outlet closure 36 is then gradually opened to a required degree when the blades 35 act as shovels, catch the concrete and force it out through the discharge opening.

While I have shown a preferred form of blade in Fig. 4, the cross sections of a blade shown in Figs. 5, 6 and 7 are equally as appllcable to this process as long as they are so dlsposed within the tank that they will not rupture the surface of the mixture nor agitate the mass when in the conditioning rotation and that they act as shovels as explained above when in discharging rot-a tion.

The advantages of a concrete conditioner aeeaeao as disclosed herein are obvious. e entire hoisting mechanism used heretofore to elevate the front end of the tank in order to discharge its contents, is entirely eliminated. ll'he cost of a conditioning unit as shown in the present invention is therefore greatly reduced.

ll want it clearly understood that the in vention is not to be limited to the specific construction illustrated in the drawings, many modifications thereof falling within the scope of the appended claims being apparent to those'skilled in the art.

What it claim as new, is:

.l. Conditioning means for ready-m1xed concrete comprising a cylindrical tank having an outlet, means to rotate the tank in one direction for conditioning and a reverse direction for discharging, and blades spirally disposed along the er wall of the said tank extending to the said outlet at an obtuse angle with the said wall to prevent rupture of the surface of the concrete within the tank when rotated tor conditioning and adapted to-eject the concrete through the said outlet when rotated for discharging.

2. Conditioning means for ready-mixed concrete comprising a cylindrical tank having a filling opening provided with a suitable closure in its cylindrical wall and an outlet substantially in alignment with its longitudinal axis, means to rotate the tank in one direction for conditioning and a reverse direction for discharging, and blades spirally disposed along the inner wall of the said tank extending to the said outlet atan obtuse angle with the said wall to prevent rupture of the surface of the concrete within the tank when rotated for conditioning and adapted to eject the concrete through the said outlet when rotated for discharging.

3. Conditioning means for ready-mixed concrete comprising a cylindrical tank having a conical outlet, an adjustable closure to the said outlet, means to rotate the tank in one direction for conditioning and a reverse direction for discharging, and blades spirally disposed along the inner wall of the said tank extending to the said outlet at an obtuse angle with the said wall to prevent rupture of the surface of the concrete within the tank when rotated for conditioning and adapted to eject the concrete through the said outlet when rotated for discharging.

4. Apparatus .for transporting readymixed concrete from a mixing plant to a place of usage comprising a vehicle, a cylindrical rotatable tank having an outlet mounted on the vehicle, means to rotate the tank'inonc direction for conditioning and a reverse direction for discharging, and blades spirally disposed along the inner wall of the said tank extending to the said outlet at an obtuse angle with the said wall to prevent ru ture of the surface of the concrete within t 'e tank when rotated for conditioning and adapted to eject the concrete through the said outlet when rotated for discharging.

5. Apparatus for transporting readymixed concrete from a mixing plant to a place of usage comprising a vehicle, a cylindrical tank mounted on the vehicle having a filling opening provided with a suitable closure in its cylindrical wall and an outlet substantially in alignment with its longitudinal axis, means to rotate the tank in one direction for conditioning and a reverse direction for discharging, and blades spirally disposed along the inner wall of the said tank extending to the said outlet at an obtuse angle with the said wall to prevent rupture of the surface of the concrete within the tank when rotated for conditioning and adapted to eject the concrete through the said outlet when rotated for discharging.

6. Apparatus for transporting readymixed concrete from a mixing plant to a place of usage comprising a vehicle, a cylindrical tank mounted on the vehicle having a conical outlet, an adjustable closure to the said outlet, means to rotate the tank in one direction for conditioning and a reverse direction for discharging, and blades spirally disposed along the inner wall of the said tank extending to the said outlet at an obtuse angle with the said wall to prevent rupture of the surface of the concrete within the tank when rotated for conditioning and adapted to eject the concrete through the said outlet when rotated for discharging.

7. Conditioning means for ready-mixed concrete comprising a cylindrical'tank having an outlet, means to rotate the tank in one direction for conditioning the reverse direc-' tion for discharging, and continuous blades spirally disposed immediately adjacent the inner wall of the said tank extending to the said out-let at an obtuse angle with the said wall adapted to be withdrawn from theconcrete without a 'tating the same when the tank is rotated or conditioning and to eject the concrete through the said outlet when rotated for discharging.

8. Conditioning means for ready-mixed concrete comprising a cylindrical tank having an outlet, means to rotate the tank in one direction for conditioning and a reverse direction for discharging, and blades spirally disposed along the inner wall of the said tank extending to the said outlet, the said blades being of substantially oblique triangular cross section, having its base immediately adjacent the said wall, and its longer side substantially at an obtuse angle with the said wall for the purpose specified.

9. Conditioning means for ready-mixed v concrete by means of a combined slow, rolling and flowing motion comprising a cylindrical tank having an outlet, means, to rotate the my hand.

EDWARD A. HOFFMANN. 

